Description

Overview

Ceph is a distributed storage and network file system designed to provide
excellent performance, reliability, and scalability.

This charm deploys a Ceph cluster.
juju

Usage

The ceph charm has two pieces of mandatory configuration for which no defaults
are provided. You must set these configuration options before deployment or the charm will not work:

fsid:
uuid specific to a ceph cluster used to ensure that different
clusters don't get mixed up - use `uuid` to generate one.
monitor-secret:
a ceph generated key used by the daemons that manage to cluster
to control security. You can use the ceph-authtool command to
generate one:
ceph-authtool /dev/stdout --name=mon. --gen-key

These two pieces of configuration must NOT be changed post bootstrap; attempting
to do this will cause a reconfiguration error and new service units will not join
the existing ceph cluster.

The charm also supports the specification of storage devices to be used in the
ceph cluster.

osd-devices:
A list of devices that the charm will attempt to detect, initialise and
activate as ceph storage.
This can be a superset of the actual storage devices presented to each
service unit and can be changed post ceph bootstrap using `juju set`.
The full path of each device must be provided, e.g. /dev/vdb.
For Ceph >= 0.56.6 (Raring or the Grizzly Cloud Archive) use of
directories instead of devices is also supported.

At a minimum you must provide a juju config file during initial deployment
with the fsid and monitor-secret options (contents of cepy.yaml below):

Contact Information

Authors

Ceph

Technical Footnotes

This charm uses the new-style Ceph deployment as reverse-engineered from the
Chef cookbook at https://github.com/ceph/ceph-cookbooks, although we selected
a different strategy to form the monitor cluster. Since we don't know the
names or addresses of the machines in advance, we use the relation-joined
hook to wait for all three nodes to come up, and then write their addresses
to ceph.conf in the "mon host" parameter. After we initialize the monitor
cluster a quorum forms quickly, and OSD bringup proceeds.

The osds use so-called "OSD hotplugging". ceph-disk prepare is used to
create the filesystems with a special GPT partition type. udev is set up
to mount such filesystems and start the osd daemons as their storage becomes
visible to the system (or after udevadm trigger).

The Chef cookbook mentioned above performs some extra steps to generate an OSD
bootstrapping key and propagate it to the other nodes in the cluster. Since
all OSDs run on nodes that also run mon, we don't need this and did not
implement it.

See the documentation for more information on Ceph monitor cluster deployment strategies and pitfalls.

(string)
User provided Ceph configuration. Supports a string representation of
a python dictionary where each top-level key represents a section in
the ceph.conf template. You may only use sections supported in the
template.
.
WARNING: this is not the recommended way to configure the underlying
services that this charm installs and is used at the user's own risk.
This option is mainly provided as a stop-gap for users that either
want to test the effect of modifying some config or who have found
a critical bug in the way the charm has configured their services
and need it fixed immediately. We ask that whenever this is used,
that the user consider opening a bug on this charm at
http://bugs.launchpad.net/charms providing an explanation of why the
config was needed so that we may consider it for inclusion as a
natively supported config in the the charm.

(string)
Cloud instances provider ephermeral storage which is normally mounted
on /mnt.
.
Providing this option will force an unmount of the ephemeral device
so that it can be used as a OSD storage device. This is useful for
testing purposes (cloud deployment is not a typical use case).

(boolean)
By default, the charm will raise errors if a whitelisted device is found,
but for some reason the charm is unable to initialize the device for use
by Ceph.
.
Setting this option to 'True' will result in the charm classifying such
problems as warnings only and will not result in a hook error.

(string)
This value will become the mon. key. To generate a suitable value use:
.
ceph-authtool /dev/stdout --name=mon. --gen-key
.
This configuration element is mandatory and the service will fail on
install if it is not provided.

(string)
Used by the nrpe-external-master subordinate charm.
A string that will be prepended to instance name to set the host name
in nagios. So for instance the hostname would be something like:
juju-myservice-0
If you're running multiple environments with the same services in them
this allows you to differentiate between them.

(string)
The devices to format and set up as osd volumes.
.
These devices are the range of devices that will be checked for and
used across all service units, in addition to any volumes attached
via the --storage flag during deployment.
.
For ceph >= 0.56.6 these can also be directories instead of devices - the
charm assumes anything not starting with /dev is a directory instead.

(int)
Ceph osd journal size. The journal size should be at least twice the
product of the expected drive speed multiplied by filestore max sync
interval. However, the most common practice is to partition the journal
drive (often an SSD), and mount it such that Ceph uses the entire
partition for the journal.
.
Only supported with ceph >= 0.48.3.

(string)
By default, the charm will not re-format a device that already looks
as if it might be an OSD device. This is a safeguard to try to
prevent data loss.
.
Specifying this option (any value) forces a reformat of any OSD devices
found which are not already mounted.

(boolean)
If True enables IPv6 support. The charm will expect network interfaces
to be configured with an IPv6 address. If set to False (default) IPv4
is expected.
NOTE: these charms do not currently support IPv6 privacy extension. In
order for this charm to function correctly, the privacy extension must be
disabled and a non-temporary address must be configured/available on
your network interface.

(string)
Optional configuration to support use of additional sources such as:
- ppa:myteam/ppa
- cloud:trusty-proposed/kilo
- http://my.archive.com/ubuntu main
The last option should be used in conjunction with the key configuration
option.
Note that a minimum ceph version of 0.48.2 is required for use with this
charm which is NOT provided by the packages in the main Ubuntu archive
for precise but is provided in the Ubuntu cloud archive.

(string)
YAML-formatted associative array of sysctl key/value pairs to be set
persistently. By default we set pid_max, max_map_count and
threads-max to a high value to avoid problems with large numbers (>20)
of OSDs recovering. very large clusters should set those values even
higher (e.g. max for kernel.pid_max is 4194303).